09-Feb-2003 -- In the Kingdom of Saudi Arabia, instead of a scattering of 1-2 day public holidays through the year there are two 5-7 day breaks, for the celebrations at the end of Ramaḍān and at the climax of the Ḥajj. Residents thus have the opportunity to make a long trip, either inside or outside the country. Our group of eight chose to visit the western edge of the Empty Quarter, with four of us extending the trip to 10 days with a similarly off-tarmac (although not as sandy) visit to the centre of the country. The 10 day round trip was 1,300 km off road, plus another 1,700 km on tarmac positioning the vehicles. We visited 8 Confluences, four in a square on the western side of the Empty Quarter (20N 46E, 20N 47E, 19N 47E, and 19N 46E), one in the adjacent "triangle" defined by the surrounding tarmac roads (18N 45E), and three in the central plateau region (21N 44E, 22N 43E, and 23N 43E).
To reach 19N 47E from 20N 47E we (obviously!) had to drive south, crossing numerous east-west ergs. General opinion is that in this area it's easier to cross the ergs in the direction we were going (we had planned our trip taking this into account). This is because the prevailing north winds typically shape the dunes with a gentle north-facing ramp, a crest at the top, and a slip face to the south. The slip face reaches a maximum slope of 33-35 degrees before the sand starts to tumble. One progresses by driving up the ramp, finding an uncomplicated slip face, and sliding down it.
However, later in the trip we travelled "against the grain", and found it easy to spot faults in the dune line with ramps up, which it was easy to drive. In this later part of the trip we also found the tyre marks of a sole vehicle that had travelled in our direction, presumably from the Bedu camp we encountered, which we followed for about 20 km, with admiration for the way in which the driver was able to stick to the firmer areas (one of his favourite lines was to drive E-W high on the north slopes, just under the crest of the dunes).
Our skills were not as well honed, although we generally made very good progress in 2WD, reserving 4WD for more dubious stretches, and 4WD low ratio for the most gentle-footed possible extraction from soft sand. Ideally one runs into this on a slope, so that one can use gravity by going downhill to get out. At this time of year it was no hardship to keep the air conditioning off - to give us more power and to conserve fuel.
Lunch on the journey south was taken near an area carpeted with ostrich shell - continuing the egg theme, Frank demonstrated how one could tell the difference between fresh and boiled eggs by spinning them (the fresh egg spins faster and continues spinning after being momentarily stopped by fingertip pressure).
Our usual camping time found us only a few kilometres short of our target, and we camped on a sand shelf ½ way down a slip face. In the morning it took the refreshed team only a few minutes to reach the Confluence, again in a valley between ergs.
Continued at 19N 46E.